We present new results on the evolution and nucleosynthesis in rotating AGB stars. We analyse the role of the gradient of mean molecular weight in the mixing process and show that neglecting this component induces a potentially strong third dredge-up. We also quantify the impact of rotation on the structure and conclude that the effects of rotation (1) mainly concern the inner, fast rotating regions of the stars and (2) are relatively weak as long as rotational mixing does not induce a deep third dredge-up. We also focus our investigations on the s-process nucleosynthesis and show that rotational mixing tends to inhibit the production of s-elements. This results from the contamination of the 13C-rich layers responsible for the neutron production by the poisonous 14N. Our calculations also indicate that the distribution of s-process elements depends sensitively on the magnitude of the diffusion coefficient. These results suggest that rotational mixing is not the main mechanism responsible for the production of s-elements in AGB stars, but that it can influence, and in particular reduce, the final enrichment in s-elements.

This paper presents the initial results of a multi-site photometric programme to examine the extraordinary behaviour displayed by 18 R Coronae Borealis (RCB) stars in the Magellanic Clouds (MCs). RCB stars exhibit a unique variability whereby they undergo rapid declines of up to several magnitudes. These are thought to be caused by the formation of dust in the stellar environment which reduces the brightness. The monitoring programme comprised the collection of UBVRI photometric data using five telescopes located at three different southern hemisphere longitudes (Las Campanas Observatory in Chile, Mount John University Observatory in New Zealand, and the Southern African Large Telescope, SALT, in South Africa). Examination of the data acquired in the V and I filters resulted in the identification of a total of 18 RCB declines occurring in four stars. Construction of colour–magnitude diagrams (V versus V – I), during the recovery to maximum light were undertaken in order to study the unique colour behaviour associated with the RCB declines. The combined recovery slope for the four stars was determined to be 3.37 ± 0.24, which is similar to the value of 3.1 ± 0.1 calculated for galactic RCB stars (Skuljan et al. 2003). These results may imply that the nature of the dust (i.e. the particle size) is similar in both our Galaxy and the MCs.

We have constructed a Main galaxy subsample of 67777 galaxies with redshifts in the range 0.08 ≤ z ≤ 0.12 from the Sloan Digital Sky Survey Data Release 3. Using cluster analysis, two isolated Main galaxy samples were extracted from this subsample. The two isolated Main galaxy samples identified at different radii have the same properties. Additionally, we find fewer early-type galaxies in isolated Main galaxy samples than in a close double galaxy sample.

The primary present-day observables upon which theories of galaxy evolution are based are a system’s morphology, dynamics, colour, and chemistry. Individually, each provides an important constraint to any given model; in concert, the four represent a fundamental (intractable) boundary condition for chemodynamical simulations. We review the current state-of-the-art semi-analytical and chemodynamical models for the Milky Way, emphasising the strengths and weaknesses of both approaches.

We describe observations with the Mopra radiotelescope designed to assess the feasibility of the H2O Maser Southern Galactic Plane Survey. We mapped two one-square-degree regions along the Galactic plane using the new 12-mm receiver and the UNSW Mopra spectrometer. We covered the entire spectrum between 19.5 and 27.5 GHz using this setup with the main aim of finding out which spectral lines can be detected with a quick mapping survey. We report on detected emission from H2O masers, NH3 inversion transitions (1,1), (2,2) and (3,3), HC3N (3–2), as well as several radio recombination lines.

The low infrared background and high atmospheric transparency are the principal advantages of Antarctic Plateau sites for astronomy. However, the poor seeing (between 1 and 3 as) negates much of the sensitivity improvements that the Antarctic atmosphere offers, compared to mid-latitude sites such as Mauna Kea or Cerro Paranal. The seeing at mid-latitude sites, though smaller in amplitude, is dominated by turbulence at altitudes of 10–20 km. Over the Antarctic Plateau, virtually no high altitude turbulence is present in the winter. The mean square error for an astrometric measurement with a dual-beam, differential astrometric interferometer in the very narrow angle regime is proportional to the integral of h 2C 2 N(h). Therefore, sites at which the turbulence occurs only at low altitudes offer large gains in astrometric precision. We show that a modest interferometer at the South Pole can achieve 10 μ as differential astrometry 300 times faster than a comparable interferometer at a good mid-latitude site, in median conditions. Science programs that would benefit from such an instrument include planet detection and orbit determination, and astrometric observation of stars microlensed by dark matter candidates.

The performance of the mysql and oracle database systems have been compared for a selection of astronomy queries using large catalogues of up to a billion objects. The queries tested are those expected from the astronomy community: general database queries, cone searches, neighbour finding and cross matching. The catalogue preparation, sql query formulation and database performance is presented. Most of the general queries perform adequately when appropriate indexes are present in the database. Each system performs well for cone search queries when the Hierarchical Triangular Mesh spatial index is used. Neighbour finding and cross matching are not well supported in a database environment when compared to software specifically developed to solve these problems.

The recent theory of propagation and generation of waves in a pulsar’s magnetosphere is discussed. In particular we consider models of pulsar radio emission due to plasma instabilities. Wave–particle interactions can lead to quasilinear diffusion increasing a particle’s pitch-angle. The recent model of γ-ray emission from synchrotron radiation as a result of quasilinear diffusion is discussed.

We present a statistical comparison between spectral line strength variations in Coma galaxies and galaxies in three rich clusters at z ~ 0.3. Using a principal component analysis, we have transformed the observable quantities, the line strengths, into new mutually orthogonal axes and found two specific results. First, more independent parameters are required to account for the line strength variations in the distant cluster data than in the Coma data, and second, line strengths which are not correlated in the distant cluster data are strongly coupled in the Coma data. These results suggest that galaxies in clusters have been homogenised such that most of the information from the conditions present at their formation has been destroyed. Hence, it may be possible that the present-day homogeneity of early-type galaxy properties, e.g. the fundamental plane relation, does not require a single formation scenario, but that a variety of formation scenarios for different galaxies could still yield the observed behaviour of nearby galaxies.

We have measured the rotational velocity of the companion star to be Ʊrot sin i= 80 ± 10 km s ˗1 (1σ) by fitting Kurucz model spectra to our observed spectrum of the black-hole candidate GRO J1655–40. From this we have calculated q = 0·31 ± 0·08, the mass of the compact object to be M1 = 7·91 ± 3·79 Mô (1σ) and for the companion starM2 = 2·76 ± 1·79 Mô(1σ), which is consistent with previous studies. We have also determined T eff = 6500 ± 50 K and [Fe/H] = −0·15 +0·15-0·10.

In the past few years the American Physical Society (APS) has conducted a number of surveys among the graduate student population in the US and also among young researchers. The purpose was to get an idea of the career expectations of the students and how these are met later on in their life. Two of the conclusions were: (1) students want to work in a research environment, preferably academic, and (2) graduate and undergraduate programs are not preparing them well for the different challenges and goals found in industry, the private sector and national laboratories. Jobs in academia, especially tenured positions, have been difficult to obtain forcing many students to give up on their goals after one or two postdoctoral positions. Some have found jobs in other sectors but others feel frustrated that their careers have not met their expectations and are poorly ‘prepared’ for other options. In the areas of Physics and Astronomy there is not much of a job market without graduate studies. So most students must continue graduate work, in these or other fields, in order to compete well in the job market. Graduate and undergraduate programs must become more responsible for the present state of affairs and for implementing improvements. This can be done by broadening the scope of the present programs so that a student is better prepared to face the challenges of other job opportunities. We present here a BSc program designed by astronomers and physicists, at the University of Guanajuato, to try to address some of these concerns and better prepare the students for either continuing with graduate studies or finding employment in an ever-changing job market.

HI structure is seen at every scale down to the angular resolution limit of all survey telescopes. I present several examples of the structures at high Galactic latitudes with the 12 arcmin beam of the Loveli Telescope, the 2 arcmin resolution of the DRAO synthesis, as well as other indicators of finer scale structure in the interstellar medium (ISM).

It is hoped that in the near future neutrino astronomy will reach throughout and beyond our galaxy and make measurements relevant to cosmology, astrophysics, cosmic-ray and particle physics. The construction of a high-energy neutrino telescope requires a huge volume of very transparent, deeply buried material such as ocean water or ice, which acts as the medium for detecting the particles. I will describe two experiments using Antarctic ice as this medium: the AMANDA experiment employing photomultiplier tubes and RICE utilising radio receivers.

Using the formalism of Hamaker, Bregman & Sault (1996), I derive a method for the polarisation calibration of observations made with a single radio telescope. This method is particularly appropriate for observations of pulsars, where the sign and magnitude of the circular polarisation are useful for understanding the emission processes at work. I apply the method to observations of PSR J1359–6038 made using the multibeam receiver on the Parkes radio telescope.

The non-thermal filaments in the Galactic centre constitute one of the great mysteries of this region of the Galaxy. We summarise the observational data on these filaments and critically review the various theories which currently outnumber the observed filaments. We summarise our theory for the longest of these filaments, the Snake, and discuss the relevance of this model for the other filaments in the Galactic centre region. The physics involved in our model for the Snake involves much of the physics that has dominated the career of Professor Don Melrose. In particular, the diffusion of relativistic electrons in the Snake is determined from the theory of resonant scattering by Alfvén waves.

Although the approximately flat rotation curves of gas in the outskirts of spirals are generally taken as strong evidence for spherical, isothermal dark matter halos, this conclusion is often incorrect and always model-dependent. A re-examination of the old and (nearly) model-independent inversion technique for determining the surface mass density of galaxies from their kinematics is presented. The method is shown to be relatively insensitive to noise in the kinematics. Due to incomplete kinematical knowledge at large radius, however, the surface mass density is reliable only in the inner half of the galaxy, a result that also applies to traditional rotation curve fitting techniques.

Filaments of galaxies are the dominant feature of modern large-scale redshift surveys. They can account for up to perhaps half of the baryonic mass budget of the Universe and their distribution and abundance can help constrain cosmological models. However, there remains no single, definitive way in which to detect, describe, and define what filaments are and their extent. This work examines a number of physically motivated, as well as statistical, methods that can be used to define filaments and examines their relative merits.

We discuss the first applications of our newly developed Monte Carlo event generator SOPHIA to multiparticle photoproduction of relativistic protons with thermal and power-law radiation fields. The measured total cross section is reproduced in terms of excitation and decay of baryon resonances, direct pion production, diffractive scattering, and non-diffractive multiparticle production. Non-diffractive multiparticle production is described using a string fragmentation model. We demonstrate that the widely used ‘Δ-approximation’ for the photoproduction cross section is reasonable only for a restricted set of astrophysical applications. The relevance of this result for cosmic ray propagation through the microwave background and hadronic models of active galactic nuclei and gamma-ray bursts is briefly discussed.

In this paper, we give a brief summary of the talks on accretion processes in AM Herculis systems which were presented at the ANU Astrophysical Theory Centre workshop on ‘Magnetic Fields and Accretion’. One of the topics to be discussed was the mechanism that leads to the formation of magnetically funnelled accretion flows in close interacting magnetic binaries. New solutions to the Bernoulli integral indicate that the field lines must be twisted and have a strong toroidal component at the base of the funnel in order for channelled flow to be possible. The magnetic field pressure of these toroidal fields first lifts the material out of the orbital plane allowing it to ‘levitate’ before freely falling along magnetic field lines towards the stellar surface. Results of recent calculations of the thermal structure and radiation properties of accretion funnels were also presented. These new 3D calculations allow for heating by the soft X-rays originating from the accretion shock, and by magnetic heating at the base of the funnel, and determine self-consistently the thermal structure, and the continuum and line emissions, allowing for both transfer of the external radiation field and the trapping of radiation within the funnel. Calculations were also presented of the expected properties of H- and He-like Fe lines originating from the accretion shock itself at the stellar surface. These lines are predicted to be rather strong and can be used as diagnostics of the accretion flow. Finally, the stability of the accretion shock was also addressed. In particular, it was shown that radiative cooling may cause thermal instability and an oscillatory behaviour, with two competing processes coming into play: bremsstrahlung cooling, which promotes instability, and cyclotron cooling, which tends to dampen the oscillations.

We investigate structural, kinematic and chemical properties of stars and gas in the Small Magellanic Cloud (SMC) interacting with the Large Magellanic Cloud (LMC) and the Galaxy based on a series of self-consistent chemodynamical simulations. We adopt a new ‘dwarf spheroidal model’ in which the SMC initially has both old stars with a spherical spatial distribution and an extended Hi gas disk. We mainly investigate the evolution of the SMC for the last ∼3 Gyr, during which the Magellanic Stream (MS) and the Magellanic Bridge (MB) could have formed as a result of the LMC–SMC–Galaxy interaction. Our principal results, which can be tested against observations, are as follows: The final spatial distribution of the old stars projected onto the sky is spherical, even after strong LMC–SMC–Galaxy interaction, whereas that of the new ones is significantly flattened and appears to form a bar structure. Old stars have a line-of-sight velocity dispersion σ ≃ 30 km s−1 and slow rotation, with a maximum rotational velocity, V < 20 km s−1 and show asymmetry in the radial profiles. New stars have a smaller Σ than old ones and a significant amount of rotation (V/σ > 1). Hi gas shows velocity dispersions of σ = 10–40 km s−1, a high maximum rotational velocity (V ∼ 50 km s−1) and a spatial distribution similar to that of new stars. New stars with ages younger than 3 Gyr show a negative metallicity gradient in the sense that more metal-rich stars are located in the inner regions of the SMC. The MB inevitably contains old stars with surface mass densities of 6−300 × 104 M⊙ deg−2 depending on initial stellar distributions of the modeled SMC. We find that the dwarf spheroidal model can explain more self-consistently the observed kinematic properties of stars and gas, compared with another type of the model (‘the disk model’) in which the SMC initially consists of stellar and gas disks. We suggest that, to better understand its evolution, the SMC needs to be modeled as having a spheroidal component, rather than being a pure disk.